The present invention relates to superconducting electronic devices, and more specifically, a quantum-limited Josephson amplifier with spatial separation between spectrally degenerate signal and idler modes.
In circuit quantum electrodynamics, quantum computing employs nonlinear superconducting devices called qubits to manipulate and store quantum information at microwave frequencies, and resonators (e.g., as a two-dimensional (2D) planar waveguide or as a three-dimensional (3D) microwave cavity) to read out and facilitate interaction among qubits. As one example, each superconducting qubit can include one or more Josephson junctions shunted by capacitors in parallel with the junctions. The qubits are capacitively coupled to resonators (e.g., 2D or 3D microwave cavities).